Can anyone verify the head volume (cc's) of the EJ20K engine? Looking for pistons and want to make sure, if anyone has actual data on it. I've seen a couple posts but it seems sort of speculation, and Google didn't have an answer for me. :) Thanks!

which one .. the sti has differnt heads than the regular one .. not that i know the aswer to either ..

Sorry, its the EJ20K STi version 4.

im interested also. and i have no desire to tear mine apart to find out!

--keith

Ver 3-4 ej20k heads are about 45.5cc, they are the same combustion chambers as the ej20g heads(early wrx). There's no differance in combustion chamber shap or size between sti and standard with these years.

are the ports bigger on the STi vs WRX of these years?

i know the insides are massaged a little from a WRX into an STi. figured they matched ports or something to be a little different than the WRX.

--keith

There is no differance with these years with port size. Maybe the sti's got the nicer casting but that would be about it.